Study On The Analysis Of Nutritive Components,Extraction,and Application Of Phenolic Compounds From Foshou Fruit

Foshou?Citrus medica L.var.sarcodactylis Swingle?is a plant of Rutaceae,which has a history of several hundred years in China and it is also a dual-purpose resource for medicine and food.Because it contains a variety of bioactive substances,which are related to improving health status and reducing the risk of various diseases,many studies have also confirmed that Foshou fruit plays a very important role in anti-cancer,anti-oxidation,antibacterial,anti-inflammatory and hypoglycemic,so it is a potential functional food resource.In view of this,this study is divided into several stages of design and experimental research,in order to find a suitable method to extract and use these bioactive substances.The details are as follows:In the first part,the nutritional components,volatile compounds,phenolic compounds,and antioxidant properties of the peel and pulp of Foshou were determined and analyzed.Except the water content,carbohydrates and calories,the contents of nutrition,volatile compounds and phenolic compounds and antioxidant properties in the peel of Foshou were significantly higher than those in the flesh.The contents of pyridoxine,thiamine,riboflavin,copper and iron in the peel of Foshou were higher than those in the pulp.GC-MS analysis showed that there were 153,113,and 101 volatile compounds in the fruits,peel and pulp of Foshou respectively.In addition,100g Foshou fruit has a significant contribution to the recommended daily nutrient intake?RDI?.These results confirmed the potential use of Foshou fruit as a healthy food.The results of water extraction showed that total phenolic compounds of Foshou peel and pulp were 227.45 and 88.76 mg gallic acid equivalents?GAE?/100 g fresh weight?FW?respectively.In addition their IC₅₀0 of DPPH^·scavenging activity were 22.79 and 54.74?g GAE/ml,respectively.The antioxidant capacity of peel and pulp of every 100 g fresh weight of Foshou were equal to the equivalent value of Trolox 214.81 and 71.53 mg respectively.In the second part,the response s urface methodology?RSM?was used to optimize the extraction of the bioactive compounds by ultrasonic-microwave assisted extraction?UMAE?from Foshou fruit,and phenolic compounds in the extract of Foshou fruit were pre-purified and separated by SPE and T LC.RSM based on Box-Behnken design was used to determine the optimal conditions,and the following optimized UMAE processing parameters were obtained:Ultrasonic treatment time was 96.13s,Microw ave power was 305.28W and Solid/Solvent ratio was 1:37 g/ml.Under these conditions,the extraction rate of total phenols was 9.21 mg GAE/g dry weight?DW?,the IC₅₀ scavenging capacity of DPPH^·was 27.52?g GAE/ml,and the antioxidant capacity measured by ABTS^·+method was 8.79 mg Trolox equivalent?TE?/g DW.The optimized UMAE extract was superior to those obtained using microwave-assisted extraction?MAE?or conventional solvent extraction?CSE?methods.The water extract of Foshou was pre-purified by three steps of sampling,cleaning and elution with C18 SPE column.56 phenolic compounds were detected by ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry?UPLC-Q-TOF-MS?analysis.The eluate was separated to 4 bands on TLC plate with hexane:toluene:ethyl acetate:formic acid?2:5:2.5:0.5,V/V?as mobile phase.These studies had proved that UMAE is a reliable and effective method for the qualitative and quantitative extraction of phenolic compounds from the fruits of Foshou,SPE is a technology that is helpful for the Pre-purification of phenolic compounds,and can be further separated by TLC.In the third part,the microencapsulation by spray drying technology was used to protect the bioactive constituents from the extract of Foshou.The microcapsules with different formulation and encapsulation carrier agents such as gum arabic?GA?,maltodextrin?MD?,modified starch?MS?and whey protein?WP?were prepared.The properties of the microcapsules such as yield,moisture content,hygroscopicity,water activity,density,Carr's index,cohesiveness,flowability,porosity,wettability,solubility,color,particle size,thermal behavior,relative crystallinity and micrograph were measured and analyzed.The chemical structure of microcapsules powder was characterized by Fourier transform infrared spectroscopy?FT-IR?.Best results were achieved when Foshou fruit extract was encapsulated using gum arabic/maltodextrin/modified starch?GMS?formulation as carrier agents,where it had the highest encapsulation yield?89.39%?.It also achieves the best effect in density characteristic,flowability,porosi ty,wettability and relative crystallinity.In the fourth part,in order to investigate and improve the bioavailability of Foshou fruit extract,the microencapsulated Foshou fruit extract was pressed directly to prepare effervescent tablets,and the relati onship between the ingredients of the tablets and the disintegration time was investigated,and also the extractability,bioavailability and antioxidant activity of phenolic compounds in these microencapsulated effervescent tablets were evaluated by simula ted gastrointestinal digestion model in vitro.The disintegration time of the effervescent tablets prepared with GMS was the shorter?6.28 min?.The total phenol content and antioxidant activity of the effervescent tablets were determined after methanol/water extract?ME?,phosphate buffer extract?PE?,simulated digestion extract?SDE?and simulated absorption extract?SAE?.The results showed that SDE had the highest total phenol con tent?15.43mg GAE/g?and the best effect of DPPH^·scavenging(IC₅₀ is 7.40 mg/ml).Among all the effervescent tablets,GMS tablets had the highest total phenolic content,antioxidant activity,and the best extractability of phenolic compounds.The bioavailability of phenols in efferve scent tablets with maltodextrin/modified starch/whey protein?MSW?as carrier agents was the highest?90%?,while that in gum arabic/modified starch/whey protein?GSW?tablets was 73%.These results show that it is feasible to deliver the phenolic compounds in the microencapsulated Foshou fruit extract in the form of effervescent tablets and improve its bioavailability.